Application of Modified Glassy Carbon Paste Electrode for Nanomolar Determination of Adrenaline Using FFT Admittance Voltammetry in Flow Analysis

The fast Fourier transform square-wave voltammetry (FFTSWV) was used for determination of adrenaline as a new detection technique based on measurements of electrode admittance. The working electrode was a poly(1-methylpyrrole) modified glassy carbon electrode (GCE) that exhibited stable and sensitive current responses towards adrenaline. During the measurements, the potential waveform (consists of potential steps for cleaning, stripping and potential ramp) was continuously applied on the electrode. The response is generated by admittance of the redox process of adrenaline. The support electrolyte that provided a more defined and intense peak current for adrenaline determination was at 0.1 M phosphate buffer solution (PBS) at pH 4.5 at modified glassy carbon electrodes. The linear response was obtained in the range of 3.0×10-9M to 2.0×10-8M with a detection limit of 8.68×10-10 M for adrenaline by this method. The modified electrode has been successfully applicable for the determination of adrenaline in pharmaceuticals. The proposed method showed excellent stability and reproducibility.